The discount rate deserves special attention in the context of company valuation, as even small changes in its value can have significant effects on the valuation result. In practice, the rate consists of the components of base interest rate, risk premium, personal taxation, and growth discount, which are influenced by various financing strategies. The author explores the conditions under which these components of the discount rate and the sometimes contradictory underlying model assumptions can be consistently linked. To this end, the individual components are first discussed in isolation and then gradually integrated into a comprehensive valuation model under the principle of consistency. The Capital Asset Pricing Model (CAPM) applied over multiple periods serves as the model framework. A key focus of the work is the derivation and comprehensive assessment of a tax-adjusted CAPM, which is tailored to the German tax system. This topic is of great practical relevance, as the professional standards established in IDW S 1 for auditors in Germany now require the application of a simplified tax-adjusted CAPM when determining objective company values.